Numerous applicators are known in which the brush comprises a core that is formed of two branches of a wire that are twisted together, trapping bristles therebetween.
Application EP 1 938 709 discloses a device including a twisted-core brush that defines an envelope surface having a cross-section of shape that is flat along a mid-plane and defining at least one face that is parallel to the longitudinal axis of the core.
Application EP 1 236 421 describes a brush that curves around at least two axes that are not parallel to each other.
Application JP 2005-087635 relates to a mascara applicator including a twisted core that curves in the shape of an arc so as to match the shape of a set of eyelashes, the twisted core carrying a flocked applicator at its free end.
In U.S. Pat. No. 6,508,603, the brush includes three successive rectilinear portions, the first in alignment with the stem, the second sloping, and the third parallel to the first.
In U.S. Pat. No. 4,241,743, the brush curves around an axis of curvature.
In application EP 1 020 136, the shape of the brush corresponds to a run of circular arcs of the same radius of curvature.
U.S. Pat. No. 6,003,519 relates to a brush for treating a lock of hair.
There exists a need to improve certain applicators, such as applicators that include brushes.